SU1340840A1 - Method of producing billets from rimmed and semikilled grades of steel - Google Patents

Abstract

The invention relates to rolling production and can be used in enterprises of the metallurgical industry in the preparation of blanks from boiling and semi-quiescent steels. The purpose of the invention is to increase productivity, reduce metal consumption and increase yield in the production of blanks. The method involves heating the ingot from 850–920 to 1300t10 ° C for 4.5–5 h, followed by rolling on an intermediate section to a total reduction of 62–66% according to the reduction mode, to 50% reduction on one face in the conditions of free ops, then before pressing 43% in the caliber and further to 54% in the conditions of free broadening on the other side of the ingot, followed by rolling in the caliber on both sides of the ingot, finish rolling on the intermediate section at a temperature not lower, after which final rolling to the required size with a unit E reduction in E 8- 9% of the total reduction by side. 1 tab. (L 00 o 00 4 O

Description

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The invention relates to rolling production, in particular to the production of blanks from ingots of a large mass of boiling and semi-quenching steel grades.

The aim of the invention is to increase productivity, reduce metal consumption and increase yield.

The method of producing blanks involves heating the ingot from 850–920 ° C to a rolling temperature of 1300110 ° C for 4.5–5 h, rolling onto an intermediate section to 50% to 15% to one side on a smooth barrel, then 43% to caliber and to then, before compression, 54% on a smooth barrel, then, before reduction, 43% in the caliber and then, before compression, 54%, on a smooth barrel, on the other side of the ingot, followed by rolling in the caliber on both sides of the ingot; finish rolling on the intermediate section at a temperature not lower, after which the final rolling is carried out to the required size with single reductions of 8-9% of the total reduction on the side.

It has been established experimentally that for complete and uniform heating of the ingot throughout the entire ingot volume prior to deformation it is necessary to heat up for at least 4.5 hours. On the other hand, heating of ingots of boiling and semi-quiescent steels before deformation for more than 5 hours leads to burning of the foundry crusts and the formation of a large amount of scale, which in turn leads to a deterioration in quality and an increase in the consumption of metal for rolling. In addition, an increase in the heating time leads to additional gas consumption and lower

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im gran m ingot. This rolling mode ensures uniform development of the structure throughout the ingot volume due to rolling under conditions of free broadening up to 50% of one and up to 54% on the other side of the ingot. In addition, to reduce rejects for undercut and roll, the ingot rolling on the second facet must be carried out in caliber and only 43% before crimping, and further rolling in conditions of free broadening on this side of the ingot eliminates overflow of gauge, which in turn provides an improvement quality and improvement of yield. Further rolling to the intermediate section should be carried out in the caliber, excluding the rhombic nature of the intermediate section roll to avoid the marriage of finished rolled products.

Example. In the converter shop, ingots were made (smelting, casting, and crystallization) of 3 ps steel.

In order to obtain rollout of the intermediate section, ingots with a mass of 10.7 tons were each heated in heating wells of a blooming shop from 850–920 ° C to 1300110 ° C for 4.5–5 h before issuing ingots from heating 1 bar. Then, on the blooming 1300, the ingot was rolled to an intermediate section (350x350 mm) to a total reduction of 62-66% according to the reduction mode to 50% reduction under conditions of free broadening on one side of the ingot, then to 43% reduction in caliber and then to reduction 54% with free broadening on the other side of the ingot. Further rolling to the intermediate section was performed in caliber on both sides.

the ingot with the end of rolling at the temper ature of furnace productivity and the chain rate is not lower, and then in general. To improve quality

made the final rolling on the required size (80x80 mm) with a single reduction x 8-9% of the total reduction on the side.

of rolling and exclusion of metal discontinuity due to deformation stresses, the temperature of the end of rolling to the intermediate section must not be lower than 1100 ° C. Rolling on the intermediate section should be carried out according to the mode of compression to 50% reduction in conditions of free broadening on one Face of the ingot, followed by rolling on the other face of the ingot to crimping 43% in caliber and before crimping 54% in the condition of free broadening followed by rolling in caliber on both

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im gran m ingot. This rolling mode ensures uniform development of the structure throughout the ingot volume due to rolling under conditions of free broadening up to 50% of one and up to 54% on the other side of the ingot. In addition, to reduce rejects for undercut and roll, the ingot rolling on the second facet must be carried out in caliber and only 43% before crimping, and further rolling in conditions of free broadening on this side of the ingot eliminates overflow of gauge, which in turn provides an improvement quality and improvement of yield. Further rolling to the intermediate section should be carried out in the caliber, excluding the rhombic nature of the intermediate section roll to avoid the marriage of finished rolled products.

Example. In the converter shop, ingots were made (smelting, casting, and crystallization) of 3 ps steel.

In order to obtain rollout of the intermediate section, ingots with a mass of 10.7 tons were each heated in heating wells of a blooming shop from 850–920 ° C to 1300110 ° C for 4.5–5 h before issuing ingots from heating 1 bar. Then, on the blooming 1300, the ingot was rolled to an intermediate section (350x350 mm) to a total reduction of 62-66% according to the reduction mode to 50% reduction under conditions of free broadening on one side of the ingot, then to 43% reduction in caliber and then to reduction 54% with free broadening on the other side of the ingot. Further rolling to the intermediate section was performed in caliber on both sides.

ingot with the end of rolling at a temperature not lower, after which

made the final rolling on the required size (80x80 mm) with a single reduction x 8-9% of the total reduction on the side.

In order to obtain comparative data on the effectiveness of the proposed method, the same steels were processed and by a known method.

The criterion for evaluating the effectiveness of the proposed method chose the yield, expressed as a percentage relative to the rolled metal, and the metal consumption for hire in kilograms per tonne of usable rolled metal.

The results of the tests of the proposed method in comparison with the prototype are given in the table.

From the data in the table it can be seen that when producing blanks from boiling and semi-quiet steel grades by the proposed method, the yield is increased by 1.1 times, and the metal consumption for rolling is reduced by 4-7 kg per 1 ton of rolled steel compared to the known method .

Claims (1)

The use of the proposed method for producing blanks will allow rolling with higher productivity due to reduction of scrap, metal consumption for rolling and heating time of ingots for rolling. The method of obtaining blanks from boiling and semi-quiescent steels. The proposed method Lime method Compiled by M.Reutov A.Makovska Editor Tehred A.Kravchuk Proofreader A.Obruchar Order 4378/12 Circulation 480 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Rauschska nab., 4/5 Production and printing company, Uzhgorod, Projecto st., 4 including heating the ingot to the rolling temperature, rolling to an intermediate section on each face and final rolling to the required size, characterized in that, in order to increase productivity, reduce the metal consumption and increase the yield, heat The ingot to the rolling temperature is produced for 4.5-5 hours, and rolling to the intermediate section is carried out on a smooth barrel until 50% is reduced on one face, then on another face to 43% in caliber and further to reduction 54 % on a smooth barrel, followed by rolling in a caliber on both sides, while the final rolling on the intermediate section is done at a temperature not lower. 83.5 1120